This technology addresses an ever-increasing need for shape memory alloys (SMAs) in aerospace, automotive and power generation industries. The shape-memory effect is caused by a thermoelastic martensitic transformation—a reversible transformation between two different crystalline microstructures that occurs when a shape-memory alloy (SMA) is heated or cooled. An SMA is deformed in the martensite condition, and the shape recovery occurs during heating when the specimen undergoes a reverse transformation of the martensite to the parent phase. Under constrained conditions, the output stress during reversion is limited by the flow strength of the parent phase. For engineering applications, it is also essential that the shape-memory behavior is repeatable and predictable after many cycles through the transformation.
Future potential applications for the newly developed high-temperature SMAs include shape-morphing structures, actuators and valves for airplanes and vehicles, and oil and gas exploration components. This innovation can be implemented into current aerospace applications including variable geometry chevron, variable area fan nozzle, and reconfigurable rotor blade that reduce noise and increase fuel economy by using high-temperature SMA actuators to adapt to changing flight conditions.